Sample preparation and annealing effects on the ferromagnetism in Mn-doped ZnO

Authors

• Jun Zhang, University of Nebraska - LincolnFollow
• Ralph Skomski, University of Nebraska-LincolnFollow
• David J. Sellmyer, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

May 2005

Comments

Published by American Institute of Physics. J. Applied Physics 97, 10D303 (2005). ©2005 American Institute of Physics. Permission to use. http://jap.aip.org/jap/.

Abstract

Magnetic properties of Mn-doped ZnO strongly depend on sample preparation and annealing. While the samples sintered in air at 500 °C show ferromagnetism at room temperature, those sintered at 900 °C are paramagnetic. The samples sintered in vacuum show a ferromagnetic transition at 45 K, which is attributed to ferrimagnetic Mn₃O₄. With an increase of annealing temperature, the ferromagnetism observed at room temperature in the low-temperature-sintered samples is gradually suppressed and finally completely removed. These results can be understood by considering a metastable ferromagnetic phase and its stability under varying temperatures and atmospheres.